Struct CustomCfg 

pub struct CustomCfg {
    pub u64s: [u64; 4],
    pub usizes: [usize; 4],
    pub i32s: [i32; 4],
    pub bools: [bool; 4],
    pub blob: [u8; 32],
    pub blob_len: usize,
}

Plain-old-data config payload for WorkType::Custom. Every field is Copy (integers / bools / a fixed byte array) so the whole struct survives fork() byte-faithfully in the child address space — no heap pointer, no shared mapping required. Read post-fork by the worker dispatch and handed to the closure via WorkerCtx::cfg.

Variable-length data is intentionally NOT supported here: a Vec / String field stores a heap pointer; across fork the pointer is copied verbatim but the backing buffer is copy-on-write PRIVATE (not shared), so the child sees its own duplicate, never the parent’s live data. For variable-length or genuinely shared state, allocate a MAP_SHARED region in the test body and pass its address through a u64 slot (see tests/preempt_regression.rs); small inline blobs fit in blob + blob_len.

Slot meanings are caller-defined — the framework cannot know the schema of an arbitrary user closure, so it provides indexed typed arrays the test author assigns meaning to (e.g. u64s[0] = a shared region address). Construct with CustomCfg::default + the chainable setters.

Fields

u64s: [u64; 4]

General-purpose 64-bit slots (a common use: a MAP_SHARED region address as a u64).

usizes: [usize; 4]

General-purpose pointer-width slots (sizes, counts, indices).

i32s: [i32; 4]

General-purpose signed 32-bit slots (nice levels, fds, flags).

bools: [bool; 4]

General-purpose boolean flags.

blob: [u8; 32]

Fixed inline byte blob for small variable-length payloads; the valid prefix length is Self::blob_len.

blob_len: usize

Number of valid leading bytes in Self::blob (0..=32).

Implementations

impl CustomCfg

pub const fn u64_slot(self, i: usize, v: u64) -> Self

Set slot i of Self::u64s, returning self for chaining.

Panics

Panics if i >= 4 (the array length).

pub const fn usize_slot(self, i: usize, v: usize) -> Self

Set slot i of Self::usizes, returning self for chaining.

Panics

Panics if i >= 4 (the array length).

pub const fn i32_slot(self, i: usize, v: i32) -> Self

Set slot i of Self::i32s, returning self for chaining.

Panics

Panics if i >= 4 (the array length).

pub const fn bool_slot(self, i: usize, v: bool) -> Self

Set slot i of Self::bools, returning self for chaining.

Panics

Panics if i >= 4 (the array length).

pub fn blob(self, bytes: &[u8]) -> Self

Copy up to 32 bytes into Self::blob and set Self::blob_len. Input longer than 32 bytes is truncated to 32. Non-const (unlike the integer/bool slot setters) because it copies a runtime slice, which a const fn cannot express today.

Trait Implementations

impl Clone for CustomCfg

fn clone(&self) -> CustomCfg

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CustomCfg

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for CustomCfg

fn default() -> CustomCfg

Returns the “default value” for a type.

impl Hash for CustomCfg

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for CustomCfg

fn eq(&self, other: &CustomCfg) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for CustomCfg

impl Eq for CustomCfg

impl StructuralPartialEq for CustomCfg